HSC Science (Electronics) 12th Standard Board Exam - Maharashtra State Board Question Bank Solutions

If AC voltage is applied to a pure capacitor, then the voltage across the capacitor ______  

An electric bulb operates 10 V d.c. If this bulb is connected to an a.c. source and gives normal brightness, then the peak value of the source is ______ 

A coil of resistance 300Ω and inductance 1.0 H is connected across an alternating voltage of frequency `300/(2pi)` Hz, therefore phase difference between the voltage and current in the circuit is ______ 

State the equation for impedance Z in an A.C. circuit.

If the peak value of an alternating emf is 15V, what is its mean value over half cycle?

Explain term impedance and state the formula for it in the case of an LCR series circuit.

A series LCR circuit has resistance 10Ω and reactance is `7sqrt2` Ω. What is the impedance of the circuit?

Find the current in a circuit consisting of a coil and a capacitor in series with an A.C source of 110V (r.m.s.), 60Hz. The inductance of a coil is 0.80 H and its resistance is 50Ω. The capacitance of a capacitor is 8µF. 

A 0.5µF capacitor is discharged through a 10 millihenry inductor. Find the frequency of discharge. 

What is the capacitive reactance of a capacitor of 5µF at a frequency of (1) 50 Hz and (2) 20KHZ? 

What is the inductive reactance of a coil of inductance 10mH at a frequency

1.  50 Hz
2. 1000 Hz
3. 20 kHz?

Explain the term inductive reactance. State its unit and dimensions.

Obtain the expression for the applied emf and the effective resistance of the circuit when alternating emf is applied to an LR circuit.

Obtain the expression for the applied emf and the effective resistance of the circuit when alternating emf is applied to a CR circuit.

P ∝ T at constant volume is the statement of ______.

Two tanks of equal volume contain equal mass of oxygen and nitrogen at 127°C. Find the ratio of pressure in two tanks.

What is the difference between rotation and revolution?

Obtain an expression for total kinetic energy of a rolling body in the form

`1/2 (MV^2)[1+K^2/R^2]`

The photoelectric work function for a metal surface is 2.3 eV. If the light of wavelength 6800A is incident on the surface of metal, find threshold frequency and incident frequency. Will there be an emission of photoelectrons or not?

[Velocity of light c = 3 x 10⁸ m/s,

Planck’s constant, h = 6.63 * 10^-34 Js ]

The kinetic energy of a rotating body depends upon................

1. distribution of mass only.
2. angular speed only.
3. distribution of mass and angular speed.
4. angular acceleration only.